Thread: ED glass in Scopes & Binos

HD in glass is supposed to mean High density. glass that is of high density has lower refraction, yoi basically get a sharper image. But since the advent hd tv, which means high definition, a lot of acopes uses this term without necesaarily using high density glass.

ed has always had a specifc meaning , extra low dispersion, usually ed glass is used to correct ca. But on cheap scopes, when all other pieces, of glass are of low quality, having a ed lens cannot save it from being bad.